var ani = {
  easeInQuad: function(x, t, b, c, d) {
    return c * (t /= d) * t + b;
  },
  easeOutQuad: function(x, t, b, c, d) {
    return -c * (t /= d) * (t - 2) + b;
  },
  easeInOutQuad: function(x, t, b, c, d) {
    if ((t /= d / 2) < 1) return (c / 2) * t * t + b;
    return (-c / 2) * (--t * (t - 2) - 1) + b;
  },
  easeInCubic: function(x, t, b, c, d) {
    return c * (t /= d) * t * t + b;
  },
  easeOutCubic: function(x, t, b, c, d) {
    return c * ((t = t / d - 1) * t * t + 1) + b;
  },
  easeInOutCubic: function(x, t, b, c, d) {
    if ((t /= d / 2) < 1) return (c / 2) * t * t * t + b;
    return (c / 2) * ((t -= 2) * t * t + 2) + b;
  },
  easeInQuart: function(x, t, b, c, d) {
    return c * (t /= d) * t * t * t + b;
  },
  easeOutQuart: function(x, t, b, c, d) {
    return -c * ((t = t / d - 1) * t * t * t - 1) + b;
  },
  easeInOutQuart: function(x, t, b, c, d) {
    if ((t /= d / 2) < 1) return (c / 2) * t * t * t * t + b;
    return (-c / 2) * ((t -= 2) * t * t * t - 2) + b;
  },
  easeInQuint: function(x, t, b, c, d) {
    return c * (t /= d) * t * t * t * t + b;
  },
  easeOutQuint: function(x, t, b, c, d) {
    return c * ((t = t / d - 1) * t * t * t * t + 1) + b;
  },
  easeInOutQuint: function(x, t, b, c, d) {
    if ((t /= d / 2) < 1) return (c / 2) * t * t * t * t * t + b;
    return (c / 2) * ((t -= 2) * t * t * t * t + 2) + b;
  },
  easeInSine: function(x, t, b, c, d) {
    return -c * Math.cos((t / d) * (Math.PI / 2)) + c + b;
  },
  easeOutSine: function(x, t, b, c, d) {
    return c * Math.sin((t / d) * (Math.PI / 2)) + b;
  },
  easeInOutSine: function(x, t, b, c, d) {
    return (-c / 2) * (Math.cos((Math.PI * t) / d) - 1) + b;
  },
  easeInExpo: function(x, t, b, c, d) {
    return t == 0 ? b : c * Math.pow(2, 10 * (t / d - 1)) + b;
  },
  easeOutExpo: function(x, t, b, c, d) {
    return t == d ? b + c : c * (-Math.pow(2, (-10 * t) / d) + 1) + b;
  },
  easeInOutExpo: function(x, t, b, c, d) {
    if (t == 0) return b;
    if (t == d) return b + c;
    if ((t /= d / 2) < 1) return (c / 2) * Math.pow(2, 10 * (t - 1)) + b;
    return (c / 2) * (-Math.pow(2, -10 * --t) + 2) + b;
  },
  easeInCirc: function(x, t, b, c, d) {
    return -c * (Math.sqrt(1 - (t /= d) * t) - 1) + b;
  },
  easeOutCirc: function(x, t, b, c, d) {
    return c * Math.sqrt(1 - (t = t / d - 1) * t) + b;
  },
  easeInOutCirc: function(x, t, b, c, d) {
    if ((t /= d / 2) < 1) return (-c / 2) * (Math.sqrt(1 - t * t) - 1) + b;
    return (c / 2) * (Math.sqrt(1 - (t -= 2) * t) + 1) + b;
  },
  easeInElastic: function(x, t, b, c, d) {
    var s = 1.70158;
    var p = 0;
    var a = c;
    if (t == 0) return b;
    if ((t /= d) == 1) return b + c;
    if (!p) p = d * 0.3;
    if (a < Math.abs(c)) {
      a = c;
      var s = p / 4;
    } else var s = (p / (2 * Math.PI)) * Math.asin(c / a);
    return -(a * Math.pow(2, 10 * (t -= 1)) * Math.sin(((t * d - s) * (2 * Math.PI)) / p)) + b;
  },
  easeOutElastic: function(x, t, b, c, d) {
    var s = 1.70158;
    var p = 0;
    var a = c;
    if (t == 0) return b;
    if ((t /= d) == 1) return b + c;
    if (!p) p = d * 0.3;
    if (a < Math.abs(c)) {
      a = c;
      var s = p / 4;
    } else var s = (p / (2 * Math.PI)) * Math.asin(c / a);
    return a * Math.pow(2, -10 * t) * Math.sin(((t * d - s) * (2 * Math.PI)) / p) + c + b;
  },
  easeInOutElastic: function(x, t, b, c, d) {
    var s = 1.70158;
    var p = 0;
    var a = c;
    if (t == 0) return b;
    if ((t /= d / 2) == 2) return b + c;
    if (!p) p = d * (0.3 * 1.5);
    if (a < Math.abs(c)) {
      a = c;
      var s = p / 4;
    } else var s = (p / (2 * Math.PI)) * Math.asin(c / a);
    if (t < 1) return -0.5 * (a * Math.pow(2, 10 * (t -= 1)) * Math.sin(((t * d - s) * (2 * Math.PI)) / p)) + b;
    return a * Math.pow(2, -10 * (t -= 1)) * Math.sin(((t * d - s) * (2 * Math.PI)) / p) * 0.5 + c + b;
  },
  easeInBack: function(x, t, b, c, d, s) {
    if (s == undefined) s = 1.70158;
    return c * (t /= d) * t * ((s + 1) * t - s) + b;
  },
  easeOutBack: function(x, t, b, c, d, s) {
    if (s == undefined) s = 1.70158;
    return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b;
  },
  easeInOutBack: function(x, t, b, c, d, s) {
    if (s == undefined) s = 1.70158;
    if ((t /= d / 2) < 1) return (c / 2) * (t * t * (((s *= 1.525) + 1) * t - s)) + b;
    return (c / 2) * ((t -= 2) * t * (((s *= 1.525) + 1) * t + s) + 2) + b;
  },
  easeInBounce: function(x, t, b, c, d) {
    return c - ani.easeOutBounce(x, d - t, 0, c, d) + b;
  },
  easeOutBounce: function(x, t, b, c, d) {
    if ((t /= d) < 1 / 2.75) {
      return c * (7.5625 * t * t) + b;
    } else if (t < 2 / 2.75) {
      return c * (7.5625 * (t -= 1.5 / 2.75) * t + 0.75) + b;
    } else if (t < 2.5 / 2.75) {
      return c * (7.5625 * (t -= 2.25 / 2.75) * t + 0.9375) + b;
    } else {
      return c * (7.5625 * (t -= 2.625 / 2.75) * t + 0.984375) + b;
    }
  },
  easeInOutBounce: function(x, t, b, c, d) {
    if (t < d / 2) return ani.easeInBounce(x, t * 2, 0, c, d) * 0.5 + b;
    return ani.easeOutBounce(x, t * 2 - d, 0, c, d) * 0.5 + c * 0.5 + b;
  },
};
